Devices having inductive cores are important in electric and electronic apparatuses. Such devices include transformers, inductors, and electromagnets. In the past it is been relatively difficult and expensive to produce inductive devices of the scale appropriate for use in many printed circuit boards, multichip modules, integrated circuits, or micro electromechanical (“MEM”) devices. In the past such small inductive devices usually have been fabricated using a variety of mechanical operations. These operations have included stamping, or micromachining ferromagnetic materials suitable for use in as cores and then winding primary and/or secondary coils around them. Usually such a prior art inductive devices have been separate units that have to be individually mounted upon printed circuit boards or multichip modules. Such devices are often much larger in volume than many other electronic devices and, thus, it has long been a desire to reduce the size of such inductive devices.
In the prior art there has been some creation of ferromagnetic cores upon integrated circuits for use in the micro electromechanical devices. In the past most such ferromagnetic cores have been deposited on the MEM devices by sputtering, which is a relatively expensive, time-consuming, and high-temperature process. The high-temperature of sputtering processes makes them impossible to use on many types of substrates or dielectrics.
It is an object of the present invention to provide inductive cores for use in inductors, transformers, and electromagnets which can be manufactured inexpensively, which consume relatively little space, and/or which can be formed on many different substrates.